Continuous-flow steam generator

Abstract

A continuous-flow steam generator includes a combustion chamber of rectangular cross-section and combustion-chamber walls each having essentially vertically disposed evaporator tubes through which a flow medium can flow from the bottom towards the top. The tubes are connected to one another in a gas-tight manner by tube webs. In order to equalize a differing supply of heat into the evaporator tubes, a heat-absorbing surface formed from an individual evaporator tube and from the tube web assigned to that tube is smaller in the case of evaporator tubes in a middle region of the combustion-chamber wall than at a corner of the combustion chamber.

I claim: 
     
       1. A continuous-flow steam generator, comprising: a combustion chamber having a rectangular cross-section with corners and having combustion-chamber walls with middle regions;   each of said combustion-chamber walls having substantially vertically disposed evaporator tubes for upwardly conducting a flowing medium, and tube webs gas-tightly interconnecting said evaporator tubes; and   each of said evaporator tubes and at least one of said tube webs connected thereto defining a heat-absorbing surface, said heat-absorbing surfaces being smaller in said middle region of said combustion-chamber wall than at said corners of said combustion chamber.   
     
     
       2. The continuous-flow steam generator according to claim 1, wherein said tube-webs interconnecting said evaporator tubes in said middle region of each combustion chamber wall have smaller widths than at said corners of said combustion chamber. 
     
     
       3. The continuous-flow steam generator according to claim 2, wherein said widths of said tube webs are successively increased, as seen from said middle region towards each of said corners of said combustion chamber. 
     
     
       4. The continuous-flow steam generator according to claim 2, wherein said evaporator tubes of each of said combustion-chamber walls are combined into groups, said tube webs within each of said groups have an identical width, and said tube webs of different groups are different. 
     
     
       5. The continuous-flow steam generator according to claim 4, wherein said tube webs of said groups adjacent said corners of said combustion chamber have an identical width. 
     
     
       6. The continuous-flow steam generator according to claim 1, including additional tube webs connected to said evaporator tubes and projecting into said combustion chamber, at least in the vicinity of said corners of said combustion chamber. 
     
     
       7. The continuous-flow steam generator according to claim 1, wherein said evaporator tubes have an inner surface structure. 
     
     
       8. The continuous-flow steam generator according to claim 1, wherein said evaporator tubes in the vicinity of said corners of said combustion chamber have a larger outside diameter and a larger inside diameter than said evaporator tubes in said middle region of said combustion chamber walls. 
     
     
       9. The continuous-flow steam generator according to claim 1, wherein said evaporator tubes in the vicinity of said corners of said combustion chamber have a larger outside diameter than said evaporator tubes in said middle region of said combustion chamber walls. 
     
     
       10. The continuous-flow steam generator according to claim 1, wherein said evaporator tubes in the vicinity of said corners of said combustion chamber have a larger inside diameter than said evaporator tubes in said middle region of said combustion chamber walls.